Safety device for locks.



I. P. J. BIROT.

SAFETY DEVICE Foa LoKs. APPLICATION FILED NOV. 24.1913.

Lwwm. Patented Ju1y11,1916.

SAFETY DEVICE FOR LOCKS.

insonni.

Specification ol' Letters Patent.

Patented July lll, i916.

Application filed November 24, 1913. Serial N o. 802,588.

To all whom it may concern.'

Be it known that I, JEAN PIERRE JosErI-r Brno'r, citizen of the Republicof France, residing at Villa Roxane St. Lon, Bayonne, Basses-Pyrenees,in the Republic of France, have invented new and useful, Improvements inSafety Devices for Locks, of which the following is a specification.

lThis invention relates to improvements in safety devices for locks,said device comprising a stop piece which prevents the bolt beingdisplaced and which may be moved aside by a supplementary bit of thekey. The stop piece is mounted on the outside of the lock, that is tosay, on the Outside of the casing which contains the usual mechanism andon the one or other face of this casing which allows of easily applyingthe device to existing locks. The casing of the Vlock preferably carriesexterior wards with which the supplementary'bit of the key cooperates,which further increases the safety of the lock. The stop piece ispreferably elastic and the supplementary bit of the key,

which is rigidly mounted on the key stem.

pushes back the said piece by acting on an inclined plane formedthereon. rlhe stop piece is also preferably provided with a screwthreaded button and it is by means of this button that it locks the boltso that it is sulicient to unscrew this button to put the safety deviceout of action.

The annexed drawing shows by way of example the safety device arrangedaccording to the invention applied to a lock of any kind.

Figure l is a front view of the look. Fig. 2 is a section on line A-B ofFig. 1. Fig. 3 is a partial section on line D-C of Fig. l. Fig. 4 showsthe same partial section with the key in the initial position ofintroduction into the lock. Fig. 5 is a similar partial section showingthe position of the key after a half turn when it pushes back the stoppiece.

The safety device is constituted as fol` lows: On one of the walls a ofthe lock casing, is screwed or riveted by one of its ends a plate springZ2 forming a stop piece for the bolt o. This piece b carries at theother end a button Z which screws into the piece b and which engages ina corresponding cavity e of the bolt through an opening formed in thewall of the lock casing. Opposite the key hole f, and bolt andconcentrically therewith stop b comprlses an annular part b1 interruptedat b2 and of which the ends b3 are beveled so that their faces opposedto wall a of the lock form an inclined plane therewith graduallyreceding from the wall a toward the said ends.

The key g comprises the usual bit it which serves for operating the boltand a supplementary bit z' of which the end l can engage when the key isturned inthe space left free between the end 3 and the wall a. lThesupplementary bit z' is cut in any manner and on the wall of the lock oneach side of the opening 7 are symmetrically placed guards or shouldersj of whichthe cutting corresponds to that of the supplementary bit z' soas to prevent turning any key which has not the properly cut bit z'.

The operation of the device is as follows: Vhen the lock is closed thestop or spring piece b for the bolt c is applied against the wall of thelock, the button CZ engages in the corresponding cavity of the bolt andblocks the latter. After having introduced the key, directly it isturned for opening the lock in the direction of the arrow, the end l ofthe supplementary bit i engages between the wall a of the lock and theeX- tremity b3 of the spring stop Z7 and in sliding on the inclined faceof the circular part 1 forces the spring b to move away from the wall aand the button Z to pass out of its housing in the bolt. rlhe movementof rotation of the key being continued it acts on the bolt in the usualway while the end l of the bit holds the spring b separated from thewall a; of the lock and consequently the button CZ out of its housinguntil the initial turn of the key is terminated. At this moment, the keyresuming the initial position the bit i ceases to act on the spring stopwhich is forced again against the wall of the lock and the button alretakes its place in a second housing of the bolt formed to receive it,if it is desired that the safety device should operate at each turn ofthe key. The closure is effected underthe same conditions. lt will benoted that with the safety means thus constituted the key must executetwo distinct operations to open or close the lock.

The shape and size of the bit z' can be varied by Varying the shapes andsizes of the guards j mounted on the wall of the lock, and the width ofthe circular part 1 of the spring as well as its distance from the holethrough which the stem of the key passes may be also varied at will.

In a series ofv similar locks diiierent bits Vcould beremployed for thekeys of each of them.

They safety device can be applied to ther majority of locks for doors,drawers or lock andthe Wood orrmetal on which said lock is placed. F IfVthe arrangement is such that the bolt ifs'retained by the stop vin theopen position of the lock, it is impossible to close it without makinguse of the key. On the contrary the device canoperate'if desired at thelast turn of the key only.l The lock can be used without the Voperationof the bolt stop if the button d is sufliciently unscrewed.

' The bolt stop device above described can be placed on locks adapted tobe opened from both sides. yOne device only isV also used in this casebut the keyv has two supplemen-` tary bits symmetrically arranged withregard tothe main'or usual bit. Y

Y The above'v described .arrangements ar only given'by way of example,the shapes and dimensions, materials, arrangements of detail andapplications can vary without dei parting from the scope of theinvention.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is:

l. Ina lock, in combination: a lock mechanism including a bolt, a casingcontaining said mechanism and a stop piece for the bolt, mounted on saidcasing, and having opposite the key hole and concentrically therewith anannular part interrupted at one point, said stop piece being adapted tobe disengaged from the bolt by a supplementary bit of the key acting onsaid annular part, substantially as described and for the purpose setforth.

2. In a lock, in combination, a lock mechanism, including a bolt, acasing containing said mechanism, a stop piece mounted on the outside ofsaid casing and adapted to be disengaged from the bolt by asupplementary bit of the key, and guards mounted on the outside of thelock casing and having a cut corresponding to that of the supplementarybit of the key, substantially as described and for the purpose setforth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing Witnesses.l

JEAN PIERRE JOSEPH BIROT.

Witnesses A.: LINDQUET, R. JACOBE.

Copies lof this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents,

' Washington, D. C.

